My friend and I had the same problem, He could keep up with me. When his son played he would always fall behind. We had the same gear, the only difference was my buddy and I use the mouse to "drive" our toons, when his son played on his account with same computer he uses buttons A and D to "drive" his toon and I would always have to wait for him. After testing it the A and D buttons will slow you down a little bit each time you hit them.